Tile Square Footage Calculator
Calculate floor or wall area, add a purchasing allowance, and estimate boxes from coverage per box. This tool does not accept tile dimensions or plan individual pieces and layouts.
Last updated:Manual deductions do not change the displayed results. This tool has no opening-deduction or net-area input. Its allowance, boxes and cost all use the geometry you entered. If you subtract openings on paper, calculate the downstream allowance, boxes and cost manually too, unless the entered non-overlapping sections already exclude those openings.
Tip: If you only have the diameter, divide by 2 to get the radius.
L-shape = two rectangles sharing a corner.
Add one row per rectangle and we'll sum them.
How to Calculate Tile Square Footage
- Measure the installed surface — floor, wall, or backsplash. For a rectangle, multiply length × width; add separate sections and manually deduct measured untiled openings.
- Choose a purchasing allowance: net area × (1 + allowance percentage ÷ 100). Use this formula manually after any separate deductions; the widget's waste setting still acts on its entered geometry.
- Use the actual coverage per box: boxes = ceil(allowance-adjusted net area ÷ coverage per box). Here, ceil means round up to the next whole number. The widget's coverage field gives this net-based result only when its entered geometry already matches the net surface.
- Check a separate cut plan before ordering. The tool has no tile-size, grout-joint, individual-piece, or layout inputs. The manual examples below explain why an area estimate can differ from a physical tile count.
For a 10 × 8 ft wall excluding a 3 × 7 ft opening, net area is 80 − 21 = 59 sq ft. With an illustrative 10% allowance, 59 × 1.10 = 64.9 sq ft; at 10 sq ft/box, ceil(64.9 ÷ 10) = 7 boxes. At an assumed $4/sq ft, the net-area-based allowance estimate is $259.60, while seven whole boxes covering 70 sq ft would cost $280 at that material rate. Leaving the original 10 × 8 dimensions in the widget instead shows 9 boxes and $352 on 88 allowance-adjusted sq ft. Its cost is an area-price estimate, not a whole-box invoice.
Choosing an Allowance Without a Layout Promise
The 10% and 15% allowances used below are illustrative purchasing assumptions, not recommended rates for particular patterns. Actual needs depend on the field dimensions, tile dimensions, pattern, edge cuts, reusable offcuts, and breakage. Keep repair reserves identifiable so they are not counted twice. A percentage cannot replace a cut plan; see the centered edge-cut example.
Nominal Tile-Area Equivalents for Common Sizes
This table treats every listed dimension as exact. Tile face area in square feet = length in inches × width in inches ÷ 144. The last column is ceil(100 ÷ tile face area), with whole-number rounding only: no purchasing allowance, joint spacing, perimeter gaps, or layout calculation. These are nominal area equivalents, not a guarantee that the listed number of physical tiles will cover a particular room.
| Assumed Exact Tile Dimensions | Face Area (sq ft each) | Nominal Equivalents for 100 sq ft, Rounded Up |
|---|---|---|
| 4 × 4 in | 1/9 | 900 |
| 6 × 6 in | 0.25 | 400 |
| 8 × 8 in | 4/9 | 225 |
| 12 × 12 in | 1 | 100 |
| 12 × 24 in | 2 | 50 |
| 18 × 18 in | 2.25 | 45 |
| 24 × 24 in | 4 | 25 |
For 100 sq ft plus an example 10% allowance, the purchasing area is 110 sq ft: 110 nominal 12 × 12 equivalents, 55 nominal 12 × 24 equivalents, or ceil(110 ÷ 2.25) = 49 nominal 18 × 18 equivalents. A product's nominal size may differ from its actual dimensions. Joint spacing, saw kerf (material lost to the blade), cuts, and layout must be checked separately.
Example: 8 × 10 Bathroom Area Estimate
- Installed area: 8 × 10 = 80 sq ft.
- Illustrative allowance: 10% → 88 sq ft.
- Nominal equivalents at exact 12 × 12 inch dimensions: 88 ÷ 1 = 88.
- If labeled box coverage is 10 sq ft: ceil(88 ÷ 10) = 9 boxes, providing 90 sq ft of labeled coverage.
This is area-to-box arithmetic only. Verify the actual cut plan and supplier's selling units before treating it as an order quantity.
Worked Layout: Centered Edge Cuts in a 103 × 62 Inch Field
Assume an available rectangular tiled field of 103 in × 62 in, measured after separately specified perimeter gaps have already been deducted. Use actual square tiles measuring exactly 12 in × 12 in and assumed 1/8 in (0.125 in) internal joints. These dimensions and joint widths are an arithmetic example, not an installation recommendation. Perimeter gaps are not additional internal joints in these equations.
Center the layout in both directions
- 9 columns: seven full 12 in tiles, two equal 9 in edge cuts, and eight joints: 7 × 12 + 2 × 9 + 8 × 0.125 = 103 in.
- 6 rows: four full 12 in tiles, two equal 6.6875 in edge cuts, and five joints: 4 × 12 + 2 × 6.6875 + 5 × 0.125 = 62 in.
Both edge-cut dimensions, 9 in and 6.6875 in, exceed half of the 12 in tile. That describes this example; it is not a minimum edge-width standard.
| Position Type | Finished Piece Dimensions | Tile Positions |
|---|---|---|
| Interior | 12 × 12 in | 7 × 4 = 28 |
| Left and right edges, excluding corners | 9 × 12 in | 2 × 4 = 8 |
| Top and bottom edges, excluding corners | 12 × 6.6875 in | 2 × 7 = 14 |
| Corners | 9 × 6.6875 in | 4 |
The layout has 9 × 6 = 54 tile positions. This cut plan assigns one uncut tile blank to each position, with no offcut reuse: 28 + 8 + 14 + 4 = 54 blanks. That is before breakage, repair reserves, and box rounding, not an optimal plan or a minimum for every possible layout. If sold in boxes of 6 tiles, 54 ÷ 6 = 9 boxes for the base cut plan only; any additional allowance must be considered separately.
Why the area method gives a different answer
- Field area: 103 × 62 = 6,386 sq in, including the internal joints.
- Nominal area equivalents: ceil(103 × 62 ÷ 144) = ceil(44.3472…) = 45.
- With an illustrative 10% area allowance: ceil(103 × 62 ÷ 144 × 1.10) = ceil(48.7819…) = 49.
Neither 45 nor 49 is a cut plan. Area division cannot locate edge pieces or determine whether offcuts fit other positions.
Compare a corner-start layout
Starting the 62 in direction with full tiles leaves a narrow far-edge cut: 62 − 5 × 12 − 5 × 0.125 = 1.375 in. The centered arrangement instead has two 6.6875 in edge cuts. This comparison illustrates a layout choice, not a required minimum edge size.
For an actual plan, recheck tile dimensions and product tolerances, specified joint width, saw kerf, perimeter gaps, out-of-square boundaries, and usable offcuts. These can change the cut dimensions or tile count. Confirm the installation details separately; this calculator does not validate them.
Walls, Backsplashes, and Trim
Measure the actual height and length of each tiled wall section rather than assuming a standard backsplash height. Add the areas, then manually deduct measured openings where no tile will be installed. Small outlet openings can still require a whole tile blank to cut around them, so their area deductions do not directly translate into fewer tiles to buy.
For example, a measured 10 ft × 4 ft tiled section is 40 sq ft; an illustrative 10% allowance gives 44 sq ft before box rounding. Measure exposed edges separately for trim: use edge length, available trim-piece lengths, and corner cuts rather than the field's square footage.
Grout, Mortar, and Sealer Are Separate Estimates
Tile purchasing allowance includes material that may become offcuts, breakage, or stored spares. Do not use that extra area as the installed area for grout or mortar.
- Grout: use installed area, actual tile dimensions, joint width and depth, tile profile, and the selected manufacturer's coverage data. There is no universal pounds-per-square-foot rate.
- Mortar or other setting material: use installed area and the selected system's product instructions for the actual substrate, tile profile, trowel, and application method. This calculator does not determine compatibility or bag coverage.
- Sealer: first check whether the selected tile and grout require it. If specified, use the product's coverage, coat count, and maintenance instructions for the surface being treated.
Pattern Choices Need Their Own Cut Plan
Straight, running-bond, diagonal, herringbone, and basketweave patterns place edges and joints differently. Draw the selected pattern using actual product dimensions and the intended joint spacing; check boundaries, niches, transitions, and trim. Do not infer a fixed waste percentage, allowable offset, or product compatibility from the pattern name.
Example: 10 × 12 Kitchen Area and Box Arithmetic
- Installed area: 10 × 12 = 120 sq ft.
- Illustrative 15% purchasing allowance: 120 × 1.15 = 138 sq ft, not a guaranteed allowance for a diagonal or other layout.
- At exact 12 × 24 inch dimensions: 138 ÷ 2 = 69 nominal tile-area equivalents.
- If a box contains 6 such tiles and its stated coverage is 12 sq ft: ceil(69 ÷ 6) = ceil(138 ÷ 12) = 12 boxes.
- Purchased quantity in this arithmetic example: 12 × 6 = 72 tiles, or 144 sq ft of face area.
This is purchasing math, not a layout or installation-material specification. Estimate grout and mortar from the 120 sq ft installed area and the actual joints, tile profile, and product data, not from the 138 sq ft allowance area or the 144 sq ft purchase. Round material packages only after calculating the product-specific requirement.
Frequently Asked Questions
How many 12x12 tiles are in 100 sq ft?
Using exact 12 × 12 inch dimensions, one tile has 1 sq ft of face area, so 100 sq ft equals 100 nominal tile-area equivalents. An illustrative 10% allowance makes 110 equivalents. Actual tile dimensions, joints, cuts, and usable offcuts determine the physical tile order.
How much waste should I add for tile?
There is no universal percentage for a pattern or tile size. The 10% and 15% allowances on this page are arithmetic examples, not installation recommendations. Review the cut plan, breakage allowance, repair reserves, and box rounding before ordering.
How many tiles do I need for a 10x10 floor?
A 10 × 10 ft floor is 100 sq ft. With an illustrative 10% allowance, 110 sq ft equals 110 nominal 12 × 12 equivalents, 55 nominal 12 × 24 equivalents, or ceil(110 ÷ 2.25) = 49 nominal 18 × 18 equivalents. These exact-dimension area calculations are not a layout guarantee.
Do I need extra tile for future repairs?
Consider a separately identified repair reserve rather than automatically adding a full box. Check whether your allowance already includes it, retain product and batch details, and confirm matching stock and storage needs with the supplier.
How much grout do I need per square foot?
There is no single reliable rate for every tile. Use installed area, actual tile dimensions, joint width and depth, tile profile, and the selected grout manufacturer's coverage data. Do not apply tile purchasing waste or spare-box area to grout coverage.
Should I buy tile in boxes or by the piece?
Check how the supplier sells the selected product. If full boxes are required, round the final requirement up using the labeled coverage or verified pieces per box. If individual pieces are available, confirm quantities, matching stock, and return terms before ordering.
How do I calculate backsplash tile?
Measure the actual length and height of each tiled section, add their areas, and manually deduct measured openings where tile will not be installed. Do not assume a universal height or outlet deduction. Small openings can still require cut tiles; count trim separately by measured edge length and available trim lengths.
Do I need thinset mortar along with the tile?
Tile needs a setting system appropriate to the tile, substrate, and application; this area calculator does not select it. Follow the selected system's instructions and product coverage data using installed area and the actual tile profile and application method, not the area of purchased spare tile.